Arcaro Carlos Alberto, Gutierres Vânia Ortega, Assis Renata Pires, Moreira Thais Fernanda, Costa Paulo Inácio, Baviera Amanda Martins, Brunetti Iguatemy Lourenço
Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University - UNESP, Araraquara, São Paulo, Brazil.
PLoS One. 2014 Dec 3;9(12):e113993. doi: 10.1371/journal.pone.0113993. eCollection 2014.
Knowing that curcumin has low bioavailability when administered orally, and that piperine has bioenhancer activity by inhibition of hepatic and intestinal biotransformation processes, the aim of this study was to investigate the antidiabetic and antioxidant activities of curcumin (90 mg/kg) and piperine (20 or 40 mg/kg), alone or co-administered, incorporated in yoghurt, in streptozotocin (STZ)-diabetic rats. The treatment for 45 days of STZ-diabetic rats with curcumin-enriched yoghurt improved all parameters altered in this experimental model of diabetes: the body weight was increased in association with the weight of skeletal muscles and white adipose tissues; the progressive increase in the glycemia levels was avoided, as well as in the glycosuria, urinary urea, dyslipidemia, and markers of liver (alanine and aspartate aminotransferases and alkaline phosphatase) and kidney (urinary protein) dysfunction; the hepatic oxidative stress was decreased, since the activities of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase were increased, and the levels of malondialdehyde and protein carbonyl groups were reduced. The dose of 20 mg/kg piperine also showed antidiabetic and antioxidant activities. The treatment of STZ-diabetic rats with both curcumin and 20 mg/kg piperine in yoghurt did not change the antidiabetic and antioxidant activities of curcumin; notably, the treatment with both curcumin and 40 mg/kg piperine abrogated the beneficial effects of curcumin. In addition, the alanine aminotransferase levels were further increased in diabetic rats treated with curcumin and 40 mg/kg piperine in comparison with untreated diabetic rats. These findings support that the co-administration of curcumin with a bioenhancer did not bring any advantage to the curcumin effects, at least about the antidiabetic and antioxidant activities, which could be related to changes on its biotransformation.
鉴于姜黄素口服时生物利用度较低，且胡椒碱具有通过抑制肝脏和肠道生物转化过程来增强生物活性的作用，本研究旨在探究姜黄素（90毫克/千克）和胡椒碱（20或40毫克/千克）单独或联合添加到酸奶中，对链脲佐菌素（STZ）诱导的糖尿病大鼠的抗糖尿病和抗氧化活性。用富含姜黄素的酸奶对STZ糖尿病大鼠进行45天的治疗，改善了该糖尿病实验模型中所有改变的参数：体重增加，同时骨骼肌和白色脂肪组织的重量也增加；避免了血糖水平、糖尿、尿尿素、血脂异常以及肝脏（丙氨酸和天冬氨酸转氨酶及碱性磷酸酶）和肾脏（尿蛋白）功能障碍标志物的逐渐升高；肝脏氧化应激降低，因为抗氧化酶超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶的活性增加，丙二醛和蛋白质羰基水平降低。20毫克/千克剂量的胡椒碱也显示出抗糖尿病和抗氧化活性。用姜黄素和20毫克/千克胡椒碱同时处理STZ糖尿病大鼠，并未改变姜黄素的抗糖尿病和抗氧化活性；值得注意的是，用姜黄素和40毫克/千克胡椒碱同时处理则消除了姜黄素的有益作用。此外，与未处理的糖尿病大鼠相比，用姜黄素和40毫克/千克胡椒碱处理的糖尿病大鼠丙氨酸转氨酶水平进一步升高。这些发现表明，姜黄素与生物增强剂联合使用至少在抗糖尿病和抗氧化活性方面，并未给姜黄素的效果带来任何优势，这可能与其生物转化的变化有关。
